Document Types

All API functions return a form of FsDocument<T>, which conveniently combines the data and id.

FsDocument

The immutable document type. Use this for defining functions that do not need to mutate the data.

type FsDocument<T> = Readonly<{
  id: string;
  data: T;
}>;

FsMutableDocument

All API abstractions return this mutable variant, which adds a typed update function and the original ref.

type FsMutableDocument<T> = Readonly<{
  id: string;
  data: T;
  ref: DocumentReference<T>;
  update: (data: UpdateData<T>) => Promise<void>;
  updateWithPartial: (data: PartialWithFieldValue<T>) => Promise<void>;
  delete: () => Promise<void>;
}>;

The hooks return mutable documents, but thanks to TypeScript structural typing, you can pass them along as if they were immutable FsDocument types.

update vs updateWithPartial

The update function is typed using Firestore's UpdateData<T> type, but this type does not allow you to pass nested objects partially, so it can reject data that is actually valid.

In those situations, use updateWithPartial instead. This function uses Firestore's PartialWithFieldValue<T> type. The two flavors are purely about typing and have identical behavior. Simply try update() first, and if the compiler does not accept it, try updateWithPartial().

FsMutableDocumentTx

In transactions, the type is slightly different, preserving the ability to chain transaction operations.

type FsMutableDocumentTx<T> = Readonly<{
  id: string;
  data: T;
  ref: DocumentReference<T>;
  update: (data: UpdateData<T>) => Transaction;
  updateWithPartial: (data: PartialWithFieldValue<T>) => Transaction;
  delete: () => Transaction;
}>;